Eraser for mechanical pencils



INVENTOR.

.rr-ron N EYS M. E. SAVOIE ERASER FOR MECHANICAL PENCILS Filed April 5, 945

Aug. 22, 1944.

a 2 1 1 2 w, 7 flwuwww a. 2 M l 2 2 2 m w .4 u m 1 h Ptented Aug. 22, 1944 UNITED STATES PATENT OFFICE 2 Clains.

This invention relates to an eraser for mechanical pencil and has for an object to provide an eraser holder combined with the pencil and having prope and retract mechanism similar to the lead propei and retract mechanism for feeding the eraser progressively as it becomes worn, so that a usable eraser will be obtainable for approximately the life of the pencil.

A further object is to provide a device of this character in which the eraser holding member forms a magazine for leads when using a fiat eraser and the pencil barrel forms a magazine for leads when using a round eraser.

A further object is to provide a device of the character stated in which the eraseholding member, when adapted to hold a cylindricai eraser, has its wall grooved to provide pockets adapted to receive leads.

With the above and other objects in view the invention consists of certain nove] details of construction and combinations of parts hereinaiter iully described and claimed, it being understood that various modifications may be resorted to within the scope of the appended claims without departing from the spirit or sacrificing any of the advantages of the invention.

In the accompanying drawing forming a part of this specification:

Figure 1 is a longitudinal sectional view, with parts in elevation, of a mechanicai pencil equipped with an eraser and propel and ret-act mechanism constructed in accordance with the invention.

Figure 2 is a longitudlnal sectional view of the mechanlcal pencil taken in a plane at a right angle to the plane of Figure 1.

Figure 3 is a cross sectiona view taken on the line 3-3 of Figure i.

Figure 4is a cross sectional view taken on the line 4-4 of Flgure 1.

Figure 5 is a perspective view showing the screw of the propel and retract mechanism separated and the means of attaching the eraser to the screw.

Flgure 6 is a perspective view showing the cup member of the eraser holding housing, the rubber bushing, and the member for looking the bushing to th cup member.

Figura 7 is a longitudinal sectional view of a modified form of the invention.

Figure 8 is a perspective view of the parts of the propel and retract mechanism, separated and the means for attaching the eraser to the screw mechanlsm.

Figur-e 9 is a perspective view showing propel and retract mechanism, similar to Figur-e 8, used in connection with a. flat eraser.

Figure 10 is a sectional view, with parts in elevation of a further modified form of propel and retract mechanism with eraser clamp in position.

Figure 11 is a sectional view of a still further modified form of propel and retract mechanism with modified form of eraser holder.

Figure 12 is a cross sectional view of a modifieri form of the invention.

Figure 13 is a sectional view oi' the pencil tip showing the magazine for holding leads.

Figure 14 is a cross sectional view taken on the line ll-Il of Flgure 7.

Figure 15 is a view of metal band which fits over the housing member concealing the junetlon of pencil barre] and housing member. and

Figure 16 is a development of the clamp shown in Figures 1, 2, 5 and 10.

R'eferring now to the drawing, III designates the barrel of a mechanical pencil. In carrying out one form of the invention a tubular housing ll is provided with a molded axial opening I2 which is of substantiaily cylindrical formation and which forms a magazine for leads !3, see Figure 3, the opening being provided with a reduced .extension M. of obiong form in cross section, to

slidably receive an eraser !5 also of substantially obiong cross section. As shown in Figure 7, the extension of the axial opening and the eraser may be round in cross section. The eraser projects into the opening !2, and at the inner end is provided with means to propel and retract the eraser as will now be described.

A cup shaped member IB is provided internally with screw threads l'l to receive'external screw threads ll! on the uniformiy reduced inner end of the housing. The member IB is substantially cylindrical and is flush with the outer surface of the housing and with the outer surface of the barrel ID. A projection s, one half the diameter of a sleeve 20 and threaded inside, extends from the member lG into the barrel and is surrounded by the annular sleeve 20 of rubber or other' material to secure the member e to the barrel II). The outer wall of the bushing frietionally contacts with the wall of an enlarged axial opening in the barre] 2l.

A cone shaped member 22, having an axial dimension one-half that of the bushing 20, and fitting in the opening of the bushing, is provided at its small end with an externally screw threaded shani; na which is threaded into member li. The cone-shaped member 22 rotatably connects 2 i assure the bushing !I to the member II. and the bushing connects the housing il to the barre! lil. A flange !I on the lower end of the cone-shaped member 2: holds the bushing against ac-' cidental displacement i'rom the member il and it ls held against accldental displaoernent !rom the barrel w by its irictlonal engagement with the barrel. A metal band Ilia which surrounds the barre] Io and member ll. conceals the juncture between said parts.

An elongated screw !I is threadedly engaged with the wall of an axial opening !I in the member lil and the cone 22 and its shani: na. The screw N is provided with a flattened portion 20 which is located within the bore II of the barre] lil, and which contacts with the walls oi the bore to prevent the screw and barrel from turning one with relation to the other. The screw 24 is connected to the eraser i! by s. clamp 21 which is attached to the eraser by i'our prongs t'ia. The lower side oi' the clamp 21 is, as best shown in Figure 16, provided with an opening !I through which the upper end of the screw !I passes. This end of the screw is provided with spherical elements 2! connected by a neck "a, the neck passing through the opening 28, and the spherical elements Contacting with the upper and lower surraces of the lower side of the clamp !1, to swivelly connect the clamp and screw. The clamp 21 ls provided with a slot "a to permit the clamp and the screw !I to be readily assembled. The sperical elements 29 oi' the screw 24 prevent the screw and the clamp 21 from having any relative axia movement, so as to insure the movement of the eraser IS when the screw and housing ll are turned one with reation to the other.

By holding the housing ll stationary and tuming the barrel lil on its axis the screw 24 will also be turned and will feed endwise through the members I! and 22 since the screw is held against rotation by the flattened portion 2.. During rotation of the barre] in one direction the eraser li will be propelled to project from the housing and during rotation of the barrel in the opposite direction the eraser will be retraeted into the housing.

Another form of the invention is shown in Figures 7 and 8 in which the housing 30 is provided with a cylindrical bore !i to receive a cylindrical eraser 32. The bore 3| is. as best shown in Figure 14, provided with four grooves I Ia which provide pockets for leads Mb. In this form of the invention the cup shaped member Isa, bushing lila, cone-shaped member na, and zflb are the same as previously described and are assembled with the housing 30 and barre] 36 of the pencil as previously described.

The cylindrical eraser l! is wedged into a cup shaped holder :a having oppositely disposed slots 39 in the sides to make the walls of the holder resilient to clamp the eraser flrmly in the holder. The holder is provided in the bottom with a centra] opening do. A screw ll is threadedly engaged in an axial opening extending through the members Isa and na and is held against rotation with relation to the barre! 36 by a flattened portion 44 which extends into a bore 46 oi' the barrel. A flattened portion 45 near the outer end oi' the screw is disposed adiacent to the holder 38 and the end portion is provided with a hook Il which is engaged in the opening Io in the bottom of the cup to swivelly attach the screw to the cup. The flattened portion 4B` forms a shoulder to push against the cup when the screw is ted endwlse s previously described to prone] the eraser out oi' the housing. Endwise reading oi' the screw in the opposite direction causes the hook 41 to retract the eraser into the cap.

As best shown in Figure 11 the Operating screw,

here designated a, may be provided with ball heads I! and an intermediate neck M, the neck passing through the opening in the bottom of the holder Ila, and the heads contacting with the upper and lower sides of the bottom oi' the holder. The hoder a is provided with a siot to permit the application or removal of the screw ua.

The eraser or rectangular cross section shown at I! in Figure 9, and which is identicai to II previously described, may be conflned in a cup shaped holder similar to the holder !I and the Operating screw Bl may be provided with a shoulder 02 and hook 68 similar to the shoulder ll and hook ll prevlously described.

The rectangular shape of the bore in the burrel may, as shown in Figura 12, be produced by an elongated casing il which is confined in the barre] to receive the Operating screw 'i and flattened portion S'i thereof in order to non-rotatably mount the Operating screw in the barrel.

The lead magazine may be disposed in the lower end of the mechanical pencil as shown at i! in Figure 13 and a portion of the magazine proiects beyond the upper end oi the pencil tip to attach said lower end to the barre] of the pencil.

In all forms of the invention the Operating screw is red endwise. and is operatively connected to the eraser through the various forms of connections heretoi'ore described.

From the above description it is thought that the construction and operation of the inventio n will be fuily understood without further explanation.

What is claimed is:

1. In combination with a pencil barrei, a sleeve irictionally fltted in the inner end of the ban-el, an interiorly threaded tubular member extended through the bore of the sleeve, said member having an exteriorly threaded portion proiecting outwardly of the barrel and sleeve and an enlarged inner end portion holding the member against outward displacement, a cylindrical member mounted in end to end relation with the sleeve having an interiorly threaded bore therethrough co-axial with the bore of said tubular member, said cylindrical member being provided with an enlarged interiorly threaded counter bore engaging the projecting portion oi the tubular member. that end of the cylindrical member remote from the sleeve having an interiorly threaded socket, a tubular eraser housing having its inner end exteriorly threaded and engaging said socket, a screw extended through and threadedly engaging the co-axial bores of said tubular and cylindrlcal members, said screw having a broad longitudinally flattened end slidably received in the barrel, means in the burrel to prevent rotation of said flat end. an eraser disposed for axial sliding movement in said housing, and a clamp attached to the inner end of the eraser and having swivel connection with the screw.

2. The structure deiined in claim 1 wherein the enlarged inner end oli the tubular member comprises a conical portion having a flange at its end inwardly of the barre] hearing against the inner end oi' the sleeve.

MARK E. SAVOIE. 

